1. Field of the Invention
The present invention relates to a viscous fluid heat generator, and more particularly, to a viscous fluid heat generator that includes a rotary assembly, which can be selectively connected to an external drive source via an electromagnetic clutch.
2. Description of the Related Art
Heat generators that are driven by a vehicle engine have attracted attention as an auxiliary heat source. This kind of heat generator includes a housing, a drive shaft extending through the housing and driven by the engine, and a rotor received in the housing and operatively connected to the drive shaft. Further, the heat generator has a heat-generating chamber defined within the housing, which accommodates the rotor and is filled with a required amount of a viscous fluid. The rotor shears the viscous fluid held between an inner wall surface of the heat-generating chamber and an outer surface of the rotor itself to generate frictional heat by fluid friction.
The drive shaft of the heat generator is connected to a pulley directly or by way of an electromagnetic clutch mechanism. Further, auxiliary machines for the vehicle, other than the heat generator, are also provided with respective pulleys on which power transmission belts extend. Engine output torque is distributed to the heat generator and other auxiliary machines via the power transmission belts.
However, if the drive shaft and the rotor are locked due to some malfunction of the drive mechanism of the heat generator, it will be impossible for the pulley of the heat generator to be driven. In such a case, the power transmission belt slips on the heat generator pulley, and vibrations caused by the slipping of the power transmission belt are transmitted to other auxiliary machines, resulting in noise.
It is an object of the present invention to provide a heat generator that has its driving state constantly monitored and that can be disconnected from a power transmission system of an external power immediately after an abnormality of its drive mechanism is detected.